A Sudden Visitor ( 突然の訪問者 / とつぜん のほうもんしゃ / totsuzen no houmonsha / An Unexpected Visitor ) is the tenth chapter of the Elfen Lied manga series.
Kouta wakes up to find Yuka in a much more caring and tender mood, even checking his temperature by placing her forehead on his. She also says that she gave Nyu some of her clothes, which made her look almost completely normal. Additionally, she reveals that it was her decision to move in with him and Nyu at the Maple House because she feared there would be more obscene instances like the one she walked in on just yesterday. Saying with much less anger that she still didn't forgive him for his lack of memories regarding her, she also assigns Kouta with cleaning the floor, as part of the agreement. A cheerful smile on her face barely cloaks directed vengeance for his lack of memories. Kouta reluctantly begins his task, but also thinks about the benefits of living with two girls. Any warm thoughts are cut off by a comment from a watchful Yuka, who decides to let an eager Nyu help with the cleaning. While Yuka fetches a cleaning towel, Nyu unnerves Kouta by seizing his hand and placing it on her breast, indicating he should squeeze it, apparently still remembering when he tried to change her clothes. He becomes aroused, and unsure of what to do or how to stop himself, and finds Nyu hanging off of him, squealing while he continues to squeeze. With a forced smile upon her face, Yuka walks in and gently asks what's going on before slapping him again hard across the face. Before going off to buy groceries, she offers him a warning about any more 'weird stuff' with Nyu. Kouta resolves to focus on cleaning and even hates to see her that angry.
A sudden knock at the door causes him to think that Yuka has come back, having forgotten something. In fact, it is Mayu, returning the same parasol that Yuka had dropped while on the beach last night, which had the address of the Maple House on the handle. When he asks where she found the umbrella, Mayu tells him, and he realizes that she was there with them on the beach. Asking if anyone else was there, she confirms that there were soldiers while remembering the horrifically wounded Bando. Now knowing that the police lied to him and that he did not imagine the soldiers, Kouta presses her for any other details she might remember.
A suspicious Yuka spots a pair of unfamiliar shoes as she returns from her grocery shopping trip. She becomes even more suspicious at seeing yet another girl inside until Kouta tells her that the young lady knows what happened the night of the beach attack. As they all begin to chat, Nyu's attempts to clean the hallway floor end with her slipping, sliding and hitting her head. A concerned Kouta calls to her, but as she enters the room, her face makes it clear Lucy has once again taken control.
- The cover for this chapter has a typo in the scanlation, reading "A Sudden Vistor" instead of "A Sudden Visitor."
- Yuka on this cover is appreciating the outdoors, likely in early spring due to the petals blowing about her.
- The jester-style hat and dress Yuka gives Nyu in this chapter is a favorite of Elfen Lied cosplayers, though the outfit is different than its more famous anime incarnation.
- This chapter sees the first instance of the running theme of Nyu's curiosity toward sexuality leading to incredibly awkward moments. It also marks the first time that Mayu and Wanta enter the Maple House. Like the chapter before, Lucy reverts to Nyu from a blow to the head, but this time it's caused by Nyu's clumsiness.